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[XFRM]: skb_cow_data() does not set proper owner for new skbs.
[linux-2.6/verdex.git] / drivers / md / dm-ioctl.c
blobee3c869d9701933d366dfdf18fc023eb5cef2da8
1 /*
2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8 #include "dm.h"
9
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/miscdevice.h>
13 #include <linux/init.h>
14 #include <linux/wait.h>
15 #include <linux/slab.h>
16 #include <linux/devfs_fs_kernel.h>
17 #include <linux/dm-ioctl.h>
18
19 #include <asm/uaccess.h>
20
21 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
22
23 /*-----------------------------------------------------------------
24 * The ioctl interface needs to be able to look up devices by
25 * name or uuid.
26 *---------------------------------------------------------------*/
27 struct hash_cell {
28 struct list_head name_list;
29 struct list_head uuid_list;
30
31 char *name;
32 char *uuid;
33 struct mapped_device *md;
34 struct dm_table *new_map;
35 };
36
37 struct vers_iter {
38 size_t param_size;
39 struct dm_target_versions *vers, *old_vers;
40 char *end;
41 uint32_t flags;
42 };
43
44
45 #define NUM_BUCKETS 64
46 #define MASK_BUCKETS (NUM_BUCKETS - 1)
47 static struct list_head _name_buckets[NUM_BUCKETS];
48 static struct list_head _uuid_buckets[NUM_BUCKETS];
49
50 static void dm_hash_remove_all(void);
51
52 /*
53 * Guards access to both hash tables.
54 */
55 static DECLARE_RWSEM(_hash_lock);
56
57 static void init_buckets(struct list_head *buckets)
58 {
59 unsigned int i;
60
61 for (i = 0; i < NUM_BUCKETS; i++)
62 INIT_LIST_HEAD(buckets + i);
63 }
64
65 static int dm_hash_init(void)
66 {
67 init_buckets(_name_buckets);
68 init_buckets(_uuid_buckets);
69 devfs_mk_dir(DM_DIR);
70 return 0;
71 }
72
73 static void dm_hash_exit(void)
74 {
75 dm_hash_remove_all();
76 devfs_remove(DM_DIR);
77 }
78
79 /*-----------------------------------------------------------------
80 * Hash function:
81 * We're not really concerned with the str hash function being
82 * fast since it's only used by the ioctl interface.
83 *---------------------------------------------------------------*/
84 static unsigned int hash_str(const char *str)
85 {
86 const unsigned int hash_mult = 2654435387U;
87 unsigned int h = 0;
88
89 while (*str)
90 h = (h + (unsigned int) *str++) * hash_mult;
91
92 return h & MASK_BUCKETS;
93 }
94
95 /*-----------------------------------------------------------------
96 * Code for looking up a device by name
97 *---------------------------------------------------------------*/
98 static struct hash_cell *__get_name_cell(const char *str)
99 {
100 struct hash_cell *hc;
101 unsigned int h = hash_str(str);
102
103 list_for_each_entry (hc, _name_buckets + h, name_list)
104 if (!strcmp(hc->name, str))
105 return hc;
106
107 return NULL;
108 }
109
110 static struct hash_cell *__get_uuid_cell(const char *str)
111 {
112 struct hash_cell *hc;
113 unsigned int h = hash_str(str);
114
115 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
116 if (!strcmp(hc->uuid, str))
117 return hc;
118
119 return NULL;
120 }
121
122 /*-----------------------------------------------------------------
123 * Inserting, removing and renaming a device.
124 *---------------------------------------------------------------*/
125 static inline char *kstrdup(const char *str)
126 {
127 char *r = kmalloc(strlen(str) + 1, GFP_KERNEL);
128 if (r)
129 strcpy(r, str);
130 return r;
131 }
132
133 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
134 struct mapped_device *md)
135 {
136 struct hash_cell *hc;
137
138 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
139 if (!hc)
140 return NULL;
141
142 hc->name = kstrdup(name);
143 if (!hc->name) {
144 kfree(hc);
145 return NULL;
146 }
147
148 if (!uuid)
149 hc->uuid = NULL;
150
151 else {
152 hc->uuid = kstrdup(uuid);
153 if (!hc->uuid) {
154 kfree(hc->name);
155 kfree(hc);
156 return NULL;
157 }
158 }
159
160 INIT_LIST_HEAD(&hc->name_list);
161 INIT_LIST_HEAD(&hc->uuid_list);
162 hc->md = md;
163 hc->new_map = NULL;
164 return hc;
165 }
166
167 static void free_cell(struct hash_cell *hc)
168 {
169 if (hc) {
170 kfree(hc->name);
171 kfree(hc->uuid);
172 kfree(hc);
173 }
174 }
175
176 /*
177 * devfs stuff.
178 */
179 static int register_with_devfs(struct hash_cell *hc)
180 {
181 struct gendisk *disk = dm_disk(hc->md);
182
183 devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
184 S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
185 DM_DIR "/%s", hc->name);
186 return 0;
187 }
188
189 static int unregister_with_devfs(struct hash_cell *hc)
190 {
191 devfs_remove(DM_DIR"/%s", hc->name);
192 return 0;
193 }
194
195 /*
196 * The kdev_t and uuid of a device can never change once it is
197 * initially inserted.
198 */
199 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
200 {
201 struct hash_cell *cell;
202
203 /*
204 * Allocate the new cells.
205 */
206 cell = alloc_cell(name, uuid, md);
207 if (!cell)
208 return -ENOMEM;
209
210 /*
211 * Insert the cell into both hash tables.
212 */
213 down_write(&_hash_lock);
214 if (__get_name_cell(name))
215 goto bad;
216
217 list_add(&cell->name_list, _name_buckets + hash_str(name));
218
219 if (uuid) {
220 if (__get_uuid_cell(uuid)) {
221 list_del(&cell->name_list);
222 goto bad;
223 }
224 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
225 }
226 register_with_devfs(cell);
227 dm_get(md);
228 dm_set_mdptr(md, cell);
229 up_write(&_hash_lock);
230
231 return 0;
232
233 bad:
234 up_write(&_hash_lock);
235 free_cell(cell);
236 return -EBUSY;
237 }
238
239 static void __hash_remove(struct hash_cell *hc)
240 {
241 /* remove from the dev hash */
242 list_del(&hc->uuid_list);
243 list_del(&hc->name_list);
244 unregister_with_devfs(hc);
245 dm_set_mdptr(hc->md, NULL);
246 dm_put(hc->md);
247 if (hc->new_map)
248 dm_table_put(hc->new_map);
249 free_cell(hc);
250 }
251
252 static void dm_hash_remove_all(void)
253 {
254 int i;
255 struct hash_cell *hc;
256 struct list_head *tmp, *n;
257
258 down_write(&_hash_lock);
259 for (i = 0; i < NUM_BUCKETS; i++) {
260 list_for_each_safe (tmp, n, _name_buckets + i) {
261 hc = list_entry(tmp, struct hash_cell, name_list);
262 __hash_remove(hc);
263 }
264 }
265 up_write(&_hash_lock);
266 }
267
268 static int dm_hash_rename(const char *old, const char *new)
269 {
270 char *new_name, *old_name;
271 struct hash_cell *hc;
272
273 /*
274 * duplicate new.
275 */
276 new_name = kstrdup(new);
277 if (!new_name)
278 return -ENOMEM;
279
280 down_write(&_hash_lock);
281
282 /*
283 * Is new free ?
284 */
285 hc = __get_name_cell(new);
286 if (hc) {
287 DMWARN("asked to rename to an already existing name %s -> %s",
288 old, new);
289 up_write(&_hash_lock);
290 kfree(new_name);
291 return -EBUSY;
292 }
293
294 /*
295 * Is there such a device as 'old' ?
296 */
297 hc = __get_name_cell(old);
298 if (!hc) {
299 DMWARN("asked to rename a non existent device %s -> %s",
300 old, new);
301 up_write(&_hash_lock);
302 kfree(new_name);
303 return -ENXIO;
304 }
305
306 /*
307 * rename and move the name cell.
308 */
309 unregister_with_devfs(hc);
310
311 list_del(&hc->name_list);
312 old_name = hc->name;
313 hc->name = new_name;
314 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
315
316 /* rename the device node in devfs */
317 register_with_devfs(hc);
318
319 up_write(&_hash_lock);
320 kfree(old_name);
321 return 0;
322 }
323
324 /*-----------------------------------------------------------------
325 * Implementation of the ioctl commands
326 *---------------------------------------------------------------*/
327 /*
328 * All the ioctl commands get dispatched to functions with this
329 * prototype.
330 */
331 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
332
333 static int remove_all(struct dm_ioctl *param, size_t param_size)
334 {
335 dm_hash_remove_all();
336 param->data_size = 0;
337 return 0;
338 }
339
340 /*
341 * Round up the ptr to an 8-byte boundary.
342 */
343 #define ALIGN_MASK 7
344 static inline void *align_ptr(void *ptr)
345 {
346 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
347 }
348
349 /*
350 * Retrieves the data payload buffer from an already allocated
351 * struct dm_ioctl.
352 */
353 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
354 size_t *len)
355 {
356 param->data_start = align_ptr(param + 1) - (void *) param;
357
358 if (param->data_start < param_size)
359 *len = param_size - param->data_start;
360 else
361 *len = 0;
362
363 return ((void *) param) + param->data_start;
364 }
365
366 static int list_devices(struct dm_ioctl *param, size_t param_size)
367 {
368 unsigned int i;
369 struct hash_cell *hc;
370 size_t len, needed = 0;
371 struct gendisk *disk;
372 struct dm_name_list *nl, *old_nl = NULL;
373
374 down_write(&_hash_lock);
375
376 /*
377 * Loop through all the devices working out how much
378 * space we need.
379 */
380 for (i = 0; i < NUM_BUCKETS; i++) {
381 list_for_each_entry (hc, _name_buckets + i, name_list) {
382 needed += sizeof(struct dm_name_list);
383 needed += strlen(hc->name) + 1;
384 needed += ALIGN_MASK;
385 }
386 }
387
388 /*
389 * Grab our output buffer.
390 */
391 nl = get_result_buffer(param, param_size, &len);
392 if (len < needed) {
393 param->flags |= DM_BUFFER_FULL_FLAG;
394 goto out;
395 }
396 param->data_size = param->data_start + needed;
397
398 nl->dev = 0; /* Flags no data */
399
400 /*
401 * Now loop through filling out the names.
402 */
403 for (i = 0; i < NUM_BUCKETS; i++) {
404 list_for_each_entry (hc, _name_buckets + i, name_list) {
405 if (old_nl)
406 old_nl->next = (uint32_t) ((void *) nl -
407 (void *) old_nl);
408 disk = dm_disk(hc->md);
409 nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
410 nl->next = 0;
411 strcpy(nl->name, hc->name);
412
413 old_nl = nl;
414 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
415 }
416 }
417
418 out:
419 up_write(&_hash_lock);
420 return 0;
421 }
422
423 static void list_version_get_needed(struct target_type *tt, void *needed_param)
424 {
425 size_t *needed = needed_param;
426
427 *needed += strlen(tt->name);
428 *needed += sizeof(tt->version);
429 *needed += ALIGN_MASK;
430 }
431
432 static void list_version_get_info(struct target_type *tt, void *param)
433 {
434 struct vers_iter *info = param;
435
436 /* Check space - it might have changed since the first iteration */
437 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
438 info->end) {
439
440 info->flags = DM_BUFFER_FULL_FLAG;
441 return;
442 }
443
444 if (info->old_vers)
445 info->old_vers->next = (uint32_t) ((void *)info->vers -
446 (void *)info->old_vers);
447 info->vers->version[0] = tt->version[0];
448 info->vers->version[1] = tt->version[1];
449 info->vers->version[2] = tt->version[2];
450 info->vers->next = 0;
451 strcpy(info->vers->name, tt->name);
452
453 info->old_vers = info->vers;
454 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
455 }
456
457 static int list_versions(struct dm_ioctl *param, size_t param_size)
458 {
459 size_t len, needed = 0;
460 struct dm_target_versions *vers;
461 struct vers_iter iter_info;
462
463 /*
464 * Loop through all the devices working out how much
465 * space we need.
466 */
467 dm_target_iterate(list_version_get_needed, &needed);
468
469 /*
470 * Grab our output buffer.
471 */
472 vers = get_result_buffer(param, param_size, &len);
473 if (len < needed) {
474 param->flags |= DM_BUFFER_FULL_FLAG;
475 goto out;
476 }
477 param->data_size = param->data_start + needed;
478
479 iter_info.param_size = param_size;
480 iter_info.old_vers = NULL;
481 iter_info.vers = vers;
482 iter_info.flags = 0;
483 iter_info.end = (char *)vers+len;
484
485 /*
486 * Now loop through filling out the names & versions.
487 */
488 dm_target_iterate(list_version_get_info, &iter_info);
489 param->flags |= iter_info.flags;
490
491 out:
492 return 0;
493 }
494
495
496
497 static int check_name(const char *name)
498 {
499 if (strchr(name, '/')) {
500 DMWARN("invalid device name");
501 return -EINVAL;
502 }
503
504 return 0;
505 }
506
507 /*
508 * Fills in a dm_ioctl structure, ready for sending back to
509 * userland.
510 */
511 static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
512 {
513 struct gendisk *disk = dm_disk(md);
514 struct dm_table *table;
515 struct block_device *bdev;
516
517 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
518 DM_ACTIVE_PRESENT_FLAG);
519
520 if (dm_suspended(md))
521 param->flags |= DM_SUSPEND_FLAG;
522
523 param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
524
525 if (!(param->flags & DM_SKIP_BDGET_FLAG)) {
526 bdev = bdget_disk(disk, 0);
527 if (!bdev)
528 return -ENXIO;
529
530 /*
531 * Yes, this will be out of date by the time it gets back
532 * to userland, but it is still very useful for
533 * debugging.
534 */
535 param->open_count = bdev->bd_openers;
536 bdput(bdev);
537 } else
538 param->open_count = -1;
539
540 if (disk->policy)
541 param->flags |= DM_READONLY_FLAG;
542
543 param->event_nr = dm_get_event_nr(md);
544
545 table = dm_get_table(md);
546 if (table) {
547 param->flags |= DM_ACTIVE_PRESENT_FLAG;
548 param->target_count = dm_table_get_num_targets(table);
549 dm_table_put(table);
550 } else
551 param->target_count = 0;
552
553 return 0;
554 }
555
556 static int dev_create(struct dm_ioctl *param, size_t param_size)
557 {
558 int r;
559 struct mapped_device *md;
560
561 r = check_name(param->name);
562 if (r)
563 return r;
564
565 if (param->flags & DM_PERSISTENT_DEV_FLAG)
566 r = dm_create_with_minor(MINOR(huge_decode_dev(param->dev)), &md);
567 else
568 r = dm_create(&md);
569
570 if (r)
571 return r;
572
573 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
574 if (r) {
575 dm_put(md);
576 return r;
577 }
578
579 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
580
581 r = __dev_status(md, param);
582 dm_put(md);
583
584 return r;
585 }
586
587 /*
588 * Always use UUID for lookups if it's present, otherwise use name or dev.
589 */
590 static inline struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
591 {
592 if (*param->uuid)
593 return __get_uuid_cell(param->uuid);
594 else if (*param->name)
595 return __get_name_cell(param->name);
596 else
597 return dm_get_mdptr(huge_decode_dev(param->dev));
598 }
599
600 static inline struct mapped_device *find_device(struct dm_ioctl *param)
601 {
602 struct hash_cell *hc;
603 struct mapped_device *md = NULL;
604
605 down_read(&_hash_lock);
606 hc = __find_device_hash_cell(param);
607 if (hc) {
608 md = hc->md;
609 dm_get(md);
610
611 /*
612 * Sneakily write in both the name and the uuid
613 * while we have the cell.
614 */
615 strncpy(param->name, hc->name, sizeof(param->name));
616 if (hc->uuid)
617 strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1);
618 else
619 param->uuid[0] = '\0';
620
621 if (hc->new_map)
622 param->flags |= DM_INACTIVE_PRESENT_FLAG;
623 else
624 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
625 }
626 up_read(&_hash_lock);
627
628 return md;
629 }
630
631 static int dev_remove(struct dm_ioctl *param, size_t param_size)
632 {
633 struct hash_cell *hc;
634
635 down_write(&_hash_lock);
636 hc = __find_device_hash_cell(param);
637
638 if (!hc) {
639 DMWARN("device doesn't appear to be in the dev hash table.");
640 up_write(&_hash_lock);
641 return -ENXIO;
642 }
643
644 __hash_remove(hc);
645 up_write(&_hash_lock);
646 param->data_size = 0;
647 return 0;
648 }
649
650 /*
651 * Check a string doesn't overrun the chunk of
652 * memory we copied from userland.
653 */
654 static int invalid_str(char *str, void *end)
655 {
656 while ((void *) str < end)
657 if (!*str++)
658 return 0;
659
660 return -EINVAL;
661 }
662
663 static int dev_rename(struct dm_ioctl *param, size_t param_size)
664 {
665 int r;
666 char *new_name = (char *) param + param->data_start;
667
668 if (new_name < (char *) (param + 1) ||
669 invalid_str(new_name, (void *) param + param_size)) {
670 DMWARN("Invalid new logical volume name supplied.");
671 return -EINVAL;
672 }
673
674 r = check_name(new_name);
675 if (r)
676 return r;
677
678 param->data_size = 0;
679 return dm_hash_rename(param->name, new_name);
680 }
681
682 static int do_suspend(struct dm_ioctl *param)
683 {
684 int r = 0;
685 struct mapped_device *md;
686
687 md = find_device(param);
688 if (!md)
689 return -ENXIO;
690
691 if (!dm_suspended(md))
692 r = dm_suspend(md);
693
694 if (!r)
695 r = __dev_status(md, param);
696
697 dm_put(md);
698 return r;
699 }
700
701 static int do_resume(struct dm_ioctl *param)
702 {
703 int r = 0;
704 struct hash_cell *hc;
705 struct mapped_device *md;
706 struct dm_table *new_map;
707
708 down_write(&_hash_lock);
709
710 hc = __find_device_hash_cell(param);
711 if (!hc) {
712 DMWARN("device doesn't appear to be in the dev hash table.");
713 up_write(&_hash_lock);
714 return -ENXIO;
715 }
716
717 md = hc->md;
718 dm_get(md);
719
720 new_map = hc->new_map;
721 hc->new_map = NULL;
722 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
723
724 up_write(&_hash_lock);
725
726 /* Do we need to load a new map ? */
727 if (new_map) {
728 /* Suspend if it isn't already suspended */
729 if (!dm_suspended(md))
730 dm_suspend(md);
731
732 r = dm_swap_table(md, new_map);
733 if (r) {
734 dm_put(md);
735 dm_table_put(new_map);
736 return r;
737 }
738
739 if (dm_table_get_mode(new_map) & FMODE_WRITE)
740 set_disk_ro(dm_disk(md), 0);
741 else
742 set_disk_ro(dm_disk(md), 1);
743
744 dm_table_put(new_map);
745 }
746
747 if (dm_suspended(md))
748 r = dm_resume(md);
749
750 if (!r)
751 r = __dev_status(md, param);
752
753 dm_put(md);
754 return r;
755 }
756
757 /*
758 * Set or unset the suspension state of a device.
759 * If the device already is in the requested state we just return its status.
760 */
761 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
762 {
763 if (param->flags & DM_SUSPEND_FLAG)
764 return do_suspend(param);
765
766 return do_resume(param);
767 }
768
769 /*
770 * Copies device info back to user space, used by
771 * the create and info ioctls.
772 */
773 static int dev_status(struct dm_ioctl *param, size_t param_size)
774 {
775 int r;
776 struct mapped_device *md;
777
778 md = find_device(param);
779 if (!md)
780 return -ENXIO;
781
782 r = __dev_status(md, param);
783 dm_put(md);
784 return r;
785 }
786
787 /*
788 * Build up the status struct for each target
789 */
790 static void retrieve_status(struct dm_table *table,
791 struct dm_ioctl *param, size_t param_size)
792 {
793 unsigned int i, num_targets;
794 struct dm_target_spec *spec;
795 char *outbuf, *outptr;
796 status_type_t type;
797 size_t remaining, len, used = 0;
798
799 outptr = outbuf = get_result_buffer(param, param_size, &len);
800
801 if (param->flags & DM_STATUS_TABLE_FLAG)
802 type = STATUSTYPE_TABLE;
803 else
804 type = STATUSTYPE_INFO;
805
806 /* Get all the target info */
807 num_targets = dm_table_get_num_targets(table);
808 for (i = 0; i < num_targets; i++) {
809 struct dm_target *ti = dm_table_get_target(table, i);
810
811 remaining = len - (outptr - outbuf);
812 if (remaining <= sizeof(struct dm_target_spec)) {
813 param->flags |= DM_BUFFER_FULL_FLAG;
814 break;
815 }
816
817 spec = (struct dm_target_spec *) outptr;
818
819 spec->status = 0;
820 spec->sector_start = ti->begin;
821 spec->length = ti->len;
822 strncpy(spec->target_type, ti->type->name,
823 sizeof(spec->target_type));
824
825 outptr += sizeof(struct dm_target_spec);
826 remaining = len - (outptr - outbuf);
827 if (remaining <= 0) {
828 param->flags |= DM_BUFFER_FULL_FLAG;
829 break;
830 }
831
832 /* Get the status/table string from the target driver */
833 if (ti->type->status) {
834 if (ti->type->status(ti, type, outptr, remaining)) {
835 param->flags |= DM_BUFFER_FULL_FLAG;
836 break;
837 }
838 } else
839 outptr[0] = '\0';
840
841 outptr += strlen(outptr) + 1;
842 used = param->data_start + (outptr - outbuf);
843
844 outptr = align_ptr(outptr);
845 spec->next = outptr - outbuf;
846 }
847
848 if (used)
849 param->data_size = used;
850
851 param->target_count = num_targets;
852 }
853
854 /*
855 * Wait for a device to report an event
856 */
857 static int dev_wait(struct dm_ioctl *param, size_t param_size)
858 {
859 int r;
860 struct mapped_device *md;
861 struct dm_table *table;
862
863 md = find_device(param);
864 if (!md)
865 return -ENXIO;
866
867 /*
868 * Wait for a notification event
869 */
870 if (dm_wait_event(md, param->event_nr)) {
871 r = -ERESTARTSYS;
872 goto out;
873 }
874
875 /*
876 * The userland program is going to want to know what
877 * changed to trigger the event, so we may as well tell
878 * him and save an ioctl.
879 */
880 r = __dev_status(md, param);
881 if (r)
882 goto out;
883
884 table = dm_get_table(md);
885 if (table) {
886 retrieve_status(table, param, param_size);
887 dm_table_put(table);
888 }
889
890 out:
891 dm_put(md);
892 return r;
893 }
894
895 static inline int get_mode(struct dm_ioctl *param)
896 {
897 int mode = FMODE_READ | FMODE_WRITE;
898
899 if (param->flags & DM_READONLY_FLAG)
900 mode = FMODE_READ;
901
902 return mode;
903 }
904
905 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
906 struct dm_target_spec **spec, char **target_params)
907 {
908 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
909 *target_params = (char *) (*spec + 1);
910
911 if (*spec < (last + 1))
912 return -EINVAL;
913
914 return invalid_str(*target_params, end);
915 }
916
917 static int populate_table(struct dm_table *table,
918 struct dm_ioctl *param, size_t param_size)
919 {
920 int r;
921 unsigned int i = 0;
922 struct dm_target_spec *spec = (struct dm_target_spec *) param;
923 uint32_t next = param->data_start;
924 void *end = (void *) param + param_size;
925 char *target_params;
926
927 if (!param->target_count) {
928 DMWARN("populate_table: no targets specified");
929 return -EINVAL;
930 }
931
932 for (i = 0; i < param->target_count; i++) {
933
934 r = next_target(spec, next, end, &spec, &target_params);
935 if (r) {
936 DMWARN("unable to find target");
937 return r;
938 }
939
940 r = dm_table_add_target(table, spec->target_type,
941 (sector_t) spec->sector_start,
942 (sector_t) spec->length,
943 target_params);
944 if (r) {
945 DMWARN("error adding target to table");
946 return r;
947 }
948
949 next = spec->next;
950 }
951
952 return dm_table_complete(table);
953 }
954
955 static int table_load(struct dm_ioctl *param, size_t param_size)
956 {
957 int r;
958 struct hash_cell *hc;
959 struct dm_table *t;
960
961 r = dm_table_create(&t, get_mode(param), param->target_count);
962 if (r)
963 return r;
964
965 r = populate_table(t, param, param_size);
966 if (r) {
967 dm_table_put(t);
968 return r;
969 }
970
971 down_write(&_hash_lock);
972 hc = __find_device_hash_cell(param);
973 if (!hc) {
974 DMWARN("device doesn't appear to be in the dev hash table.");
975 up_write(&_hash_lock);
976 return -ENXIO;
977 }
978
979 if (hc->new_map)
980 dm_table_put(hc->new_map);
981 hc->new_map = t;
982 param->flags |= DM_INACTIVE_PRESENT_FLAG;
983
984 r = __dev_status(hc->md, param);
985 up_write(&_hash_lock);
986 return r;
987 }
988
989 static int table_clear(struct dm_ioctl *param, size_t param_size)
990 {
991 int r;
992 struct hash_cell *hc;
993
994 down_write(&_hash_lock);
995
996 hc = __find_device_hash_cell(param);
997 if (!hc) {
998 DMWARN("device doesn't appear to be in the dev hash table.");
999 up_write(&_hash_lock);
1000 return -ENXIO;
1001 }
1002
1003 if (hc->new_map) {
1004 dm_table_put(hc->new_map);
1005 hc->new_map = NULL;
1006 }
1007
1008 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1009
1010 r = __dev_status(hc->md, param);
1011 up_write(&_hash_lock);
1012 return r;
1013 }
1014
1015 /*
1016 * Retrieves a list of devices used by a particular dm device.
1017 */
1018 static void retrieve_deps(struct dm_table *table,
1019 struct dm_ioctl *param, size_t param_size)
1020 {
1021 unsigned int count = 0;
1022 struct list_head *tmp;
1023 size_t len, needed;
1024 struct dm_dev *dd;
1025 struct dm_target_deps *deps;
1026
1027 deps = get_result_buffer(param, param_size, &len);
1028
1029 /*
1030 * Count the devices.
1031 */
1032 list_for_each (tmp, dm_table_get_devices(table))
1033 count++;
1034
1035 /*
1036 * Check we have enough space.
1037 */
1038 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1039 if (len < needed) {
1040 param->flags |= DM_BUFFER_FULL_FLAG;
1041 return;
1042 }
1043
1044 /*
1045 * Fill in the devices.
1046 */
1047 deps->count = count;
1048 count = 0;
1049 list_for_each_entry (dd, dm_table_get_devices(table), list)
1050 deps->dev[count++] = huge_encode_dev(dd->bdev->bd_dev);
1051
1052 param->data_size = param->data_start + needed;
1053 }
1054
1055 static int table_deps(struct dm_ioctl *param, size_t param_size)
1056 {
1057 int r = 0;
1058 struct mapped_device *md;
1059 struct dm_table *table;
1060
1061 md = find_device(param);
1062 if (!md)
1063 return -ENXIO;
1064
1065 r = __dev_status(md, param);
1066 if (r)
1067 goto out;
1068
1069 table = dm_get_table(md);
1070 if (table) {
1071 retrieve_deps(table, param, param_size);
1072 dm_table_put(table);
1073 }
1074
1075 out:
1076 dm_put(md);
1077 return r;
1078 }
1079
1080 /*
1081 * Return the status of a device as a text string for each
1082 * target.
1083 */
1084 static int table_status(struct dm_ioctl *param, size_t param_size)
1085 {
1086 int r;
1087 struct mapped_device *md;
1088 struct dm_table *table;
1089
1090 md = find_device(param);
1091 if (!md)
1092 return -ENXIO;
1093
1094 r = __dev_status(md, param);
1095 if (r)
1096 goto out;
1097
1098 table = dm_get_table(md);
1099 if (table) {
1100 retrieve_status(table, param, param_size);
1101 dm_table_put(table);
1102 }
1103
1104 out:
1105 dm_put(md);
1106 return r;
1107 }
1108
1109 /*
1110 * Pass a message to the target that's at the supplied device offset.
1111 */
1112 static int target_message(struct dm_ioctl *param, size_t param_size)
1113 {
1114 int r, argc;
1115 char **argv;
1116 struct mapped_device *md;
1117 struct dm_table *table;
1118 struct dm_target *ti;
1119 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1120
1121 md = find_device(param);
1122 if (!md)
1123 return -ENXIO;
1124
1125 r = __dev_status(md, param);
1126 if (r)
1127 goto out;
1128
1129 if (tmsg < (struct dm_target_msg *) (param + 1) ||
1130 invalid_str(tmsg->message, (void *) param + param_size)) {
1131 DMWARN("Invalid target message parameters.");
1132 r = -EINVAL;
1133 goto out;
1134 }
1135
1136 r = dm_split_args(&argc, &argv, tmsg->message);
1137 if (r) {
1138 DMWARN("Failed to split target message parameters");
1139 goto out;
1140 }
1141
1142 table = dm_get_table(md);
1143 if (!table)
1144 goto out_argv;
1145
1146 if (tmsg->sector >= dm_table_get_size(table)) {
1147 DMWARN("Target message sector outside device.");
1148 r = -EINVAL;
1149 goto out_table;
1150 }
1151
1152 ti = dm_table_find_target(table, tmsg->sector);
1153 if (ti->type->message)
1154 r = ti->type->message(ti, argc, argv);
1155 else {
1156 DMWARN("Target type does not support messages");
1157 r = -EINVAL;
1158 }
1159
1160 out_table:
1161 dm_table_put(table);
1162 out_argv:
1163 kfree(argv);
1164 out:
1165 param->data_size = 0;
1166 dm_put(md);
1167 return r;
1168 }
1169
1170 /*-----------------------------------------------------------------
1171 * Implementation of open/close/ioctl on the special char
1172 * device.
1173 *---------------------------------------------------------------*/
1174 static ioctl_fn lookup_ioctl(unsigned int cmd)
1175 {
1176 static struct {
1177 int cmd;
1178 ioctl_fn fn;
1179 } _ioctls[] = {
1180 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1181 {DM_REMOVE_ALL_CMD, remove_all},
1182 {DM_LIST_DEVICES_CMD, list_devices},
1183
1184 {DM_DEV_CREATE_CMD, dev_create},
1185 {DM_DEV_REMOVE_CMD, dev_remove},
1186 {DM_DEV_RENAME_CMD, dev_rename},
1187 {DM_DEV_SUSPEND_CMD, dev_suspend},
1188 {DM_DEV_STATUS_CMD, dev_status},
1189 {DM_DEV_WAIT_CMD, dev_wait},
1190
1191 {DM_TABLE_LOAD_CMD, table_load},
1192 {DM_TABLE_CLEAR_CMD, table_clear},
1193 {DM_TABLE_DEPS_CMD, table_deps},
1194 {DM_TABLE_STATUS_CMD, table_status},
1195
1196 {DM_LIST_VERSIONS_CMD, list_versions},
1197
1198 {DM_TARGET_MSG_CMD, target_message}
1199 };
1200
1201 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1202 }
1203
1204 /*
1205 * As well as checking the version compatibility this always
1206 * copies the kernel interface version out.
1207 */
1208 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1209 {
1210 uint32_t version[3];
1211 int r = 0;
1212
1213 if (copy_from_user(version, user->version, sizeof(version)))
1214 return -EFAULT;
1215
1216 if ((DM_VERSION_MAJOR != version[0]) ||
1217 (DM_VERSION_MINOR < version[1])) {
1218 DMWARN("ioctl interface mismatch: "
1219 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1220 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1221 DM_VERSION_PATCHLEVEL,
1222 version[0], version[1], version[2], cmd);
1223 r = -EINVAL;
1224 }
1225
1226 /*
1227 * Fill in the kernel version.
1228 */
1229 version[0] = DM_VERSION_MAJOR;
1230 version[1] = DM_VERSION_MINOR;
1231 version[2] = DM_VERSION_PATCHLEVEL;
1232 if (copy_to_user(user->version, version, sizeof(version)))
1233 return -EFAULT;
1234
1235 return r;
1236 }
1237
1238 static void free_params(struct dm_ioctl *param)
1239 {
1240 vfree(param);
1241 }
1242
1243 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1244 {
1245 struct dm_ioctl tmp, *dmi;
1246
1247 if (copy_from_user(&tmp, user, sizeof(tmp)))
1248 return -EFAULT;
1249
1250 if (tmp.data_size < sizeof(tmp))
1251 return -EINVAL;
1252
1253 dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
1254 if (!dmi)
1255 return -ENOMEM;
1256
1257 if (copy_from_user(dmi, user, tmp.data_size)) {
1258 vfree(dmi);
1259 return -EFAULT;
1260 }
1261
1262 *param = dmi;
1263 return 0;
1264 }
1265
1266 static int validate_params(uint cmd, struct dm_ioctl *param)
1267 {
1268 /* Always clear this flag */
1269 param->flags &= ~DM_BUFFER_FULL_FLAG;
1270
1271 /* Ignores parameters */
1272 if (cmd == DM_REMOVE_ALL_CMD ||
1273 cmd == DM_LIST_DEVICES_CMD ||
1274 cmd == DM_LIST_VERSIONS_CMD)
1275 return 0;
1276
1277 if ((cmd == DM_DEV_CREATE_CMD)) {
1278 if (!*param->name) {
1279 DMWARN("name not supplied when creating device");
1280 return -EINVAL;
1281 }
1282 } else if ((*param->uuid && *param->name)) {
1283 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1284 return -EINVAL;
1285 }
1286
1287 /* Ensure strings are terminated */
1288 param->name[DM_NAME_LEN - 1] = '\0';
1289 param->uuid[DM_UUID_LEN - 1] = '\0';
1290
1291 return 0;
1292 }
1293
1294 static int ctl_ioctl(struct inode *inode, struct file *file,
1295 uint command, ulong u)
1296 {
1297 int r = 0;
1298 unsigned int cmd;
1299 struct dm_ioctl *param;
1300 struct dm_ioctl __user *user = (struct dm_ioctl __user *) u;
1301 ioctl_fn fn = NULL;
1302 size_t param_size;
1303
1304 /* only root can play with this */
1305 if (!capable(CAP_SYS_ADMIN))
1306 return -EACCES;
1307
1308 if (_IOC_TYPE(command) != DM_IOCTL)
1309 return -ENOTTY;
1310
1311 cmd = _IOC_NR(command);
1312
1313 /*
1314 * Check the interface version passed in. This also
1315 * writes out the kernel's interface version.
1316 */
1317 r = check_version(cmd, user);
1318 if (r)
1319 return r;
1320
1321 /*
1322 * Nothing more to do for the version command.
1323 */
1324 if (cmd == DM_VERSION_CMD)
1325 return 0;
1326
1327 fn = lookup_ioctl(cmd);
1328 if (!fn) {
1329 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1330 return -ENOTTY;
1331 }
1332
1333 /*
1334 * Trying to avoid low memory issues when a device is
1335 * suspended.
1336 */
1337 current->flags |= PF_MEMALLOC;
1338
1339 /*
1340 * Copy the parameters into kernel space.
1341 */
1342 r = copy_params(user, &param);
1343 if (r) {
1344 current->flags &= ~PF_MEMALLOC;
1345 return r;
1346 }
1347
1348 /*
1349 * FIXME: eventually we will remove the PF_MEMALLOC flag
1350 * here. However the tools still do nasty things like
1351 * 'load' while a device is suspended.
1352 */
1353
1354 r = validate_params(cmd, param);
1355 if (r)
1356 goto out;
1357
1358 param_size = param->data_size;
1359 param->data_size = sizeof(*param);
1360 r = fn(param, param_size);
1361
1362 /*
1363 * Copy the results back to userland.
1364 */
1365 if (!r && copy_to_user(user, param, param->data_size))
1366 r = -EFAULT;
1367
1368 out:
1369 free_params(param);
1370 current->flags &= ~PF_MEMALLOC;
1371 return r;
1372 }
1373
1374 static struct file_operations _ctl_fops = {
1375 .ioctl = ctl_ioctl,
1376 .owner = THIS_MODULE,
1377 };
1378
1379 static struct miscdevice _dm_misc = {
1380 .minor = MISC_DYNAMIC_MINOR,
1381 .name = DM_NAME,
1382 .devfs_name = "mapper/control",
1383 .fops = &_ctl_fops
1384 };
1385
1386 /*
1387 * Create misc character device and link to DM_DIR/control.
1388 */
1389 int __init dm_interface_init(void)
1390 {
1391 int r;
1392
1393 r = dm_hash_init();
1394 if (r)
1395 return r;
1396
1397 r = misc_register(&_dm_misc);
1398 if (r) {
1399 DMERR("misc_register failed for control device");
1400 dm_hash_exit();
1401 return r;
1402 }
1403
1404 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1405 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1406 DM_DRIVER_EMAIL);
1407 return 0;
1408 }
1409
1410 void dm_interface_exit(void)
1411 {
1412 if (misc_deregister(&_dm_misc) < 0)
1413 DMERR("misc_deregister failed for control device");
1414
1415 dm_hash_exit();
1416 }
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